In wind-turbine operation control, an operation is employed in which, if the system voltage is reduced due to the occurrence of a power failure or the like, the connection between a wind turbine and a power system is immediately disconnected to avoid damage to a power generator etc. caused by overcurrent. On the other hand, for example, if a low-voltage event such as that shown in a voltage reduction pattern etc. required by LVRT (low voltage ride-through) occurs, the connection between the wind turbine and the power system needs to be maintained to continuously operate the wind turbine.
Patent Citation 1:
U.S. Pat. No. 6,921,985